With reference to FIGS. 1 to 3, a conventional clamping mechanism of a circular saw machine contains a base 10 on which a first clamp device 11 is disposed to clamp a workpiece A1 inside a sawing position, a second clamp device 12 for moving outwardly and inwardly to clamp the workpiece outside the sawing position, such that the workpiece A1 are clamped by the first clamp device 11 and a second clamp device 12 to be sawed by a sawing disc 16. Furthermore, the second clamp device 12 clamps the workpiece A1 outwardly after a sawing process to avoid the sawing disc 16 interfering the workpiece by vacuum suction. In addition, the first clamp device 12 includes a horizontal clamp module 13 and an upper clamp module 14, and the horizontal clamp module 13 has a fixing arm 130 for holding the workpiece A1, a first positioning block 131 located on an end portion of the fixing arm 130, and a second positioning block 132 moving horizontally relative to the first positioning block 131 to clamp or unclamp the workpiece A1. The upper clamp module 14 has a third positioning block 140 moving vertically and clamping the workpiece A1 by cooperating with the fixing arm 130. The base 10 also includes a support holder 14 on which two slide rails 150 are arranged to support the first clamp device 12 to move laterally along the first clamp device 11.
However, as shown in FIG. 2, a sawing length of a tail end of the workpiece A1 is at least a distance H1 from an outer surface of the second positioning block 132 to an inner surface of the third positioning block 140. Accordingly, the sawing length is too long to save working cost.
As illustrated in FIG. 3, iron chips 17 spray onto the support holder 15 in the sawing process and maintain between the two slide rails 150, thus damaging a servo motor 18 for driving the second clamp device 12.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.